1. Field of the Invention
This invention relates generally to the field of surgical devices and, more particularly, to a collapsible indwelling catheter for draining the urinary bladder, with the proximal part of the collapsible catheter being self retaining inside the urinary bladder.
2. Description of the Prior Art
A urinary bladder tube is used in certain patients who have undergone major surgery, or any patient who is unable to urinate. There are many causes for inability to urinate. These causes differ with age and sex. For example, a small child may not urinate because of some congenital abnormality obstructing the bladder neck or urethra. In females, inability to urinate occurs in neurological diseases, after delivery of a baby, or after major abdominal or pelvic surgery. In a male, the most common causes of inability to urinate are an obstructing prostate, neurological diseases, or after major abdominal or pelvic surgery.
It is desirable to continuously drain the bladder after major surgery at least for the purpose of monitoring the hourly urine output. It is also desirable to continuously drain the bladder by an indwelling Foley catheter in medical conditions where the measurement of hourly urine output is important to the well being of the patient.
It is also important to drain the bladder by an indwelling catheter after prostate or bladder surgery. Diverting the urine and blood will promote fast healing and prevent clots from building up in the bladder, which often cause more bleeding and severe pain.
In certain bladder or prostate surgeries, a continuous bladder irrigation is used. This is achieved by injecting fluid continuously into the bladder and simultaneously draining the bladder. This type of Foley catheter is called a three-way catheter. One port will serve as fluid injection port into the bladder. The second port is for continuous drainage of the bladder content into a large urine bag. The third port is for a valve mechanism where a balloon is inflated inside the bladder to keep the tip of the Foley catheter indwelling inside the bladder.
In certain patients, the bladder must be drained for many years, such as debilitated patients or those with neurological or spinal cord lesions. If the bladder is not drained, the pressure in the bladder will build up and the kidneys will be obstructed. Continuous bilateral kidney obstruction may lead to renal failure in a few weeks.
Therefore, the use of an indwelling catheter is very important, and could be life-saving, both in an acute and chronic long term settings.
There are many serious drawbacks to the standard rigid indwelling Foley catheter. This standard catheter must be stiff enough to be introduced into the bladder, and, as such, will continuously stretch the urethra as long as the catheter is indwelling. Continuously stretching the urethra is painful, and certain patients cannot tolerate the catheter because of the severe pain. The human urethra is always in a state of collapse except during urination, and, in the male, during ejaculation as well. Continuous stretching of the urethra is painful and may produce urethritis or urinary tract infection. A patient is given medications, sedation, and even narcotics to ease the bladder and urethral painful spasms from the rigid indwelling Foley catheter.
Thus, it is ideal if a Foley catheter has enough rigidity to be introduced, then the stiffness be replaced by softness. This could be achieved by a catheter with walls that are rigid when desired and then made soft when desired. Such a catheter would mimic the urethra in the physiological status. The pain or discomfort from an indwelling catheter will then be minimized. In addition, urethral irritation will be minimized, thus lowering the incidence of urinary tract infection.